Ukraine has expelled a Belarusian diplomat amid a spy scandal between the two neighboring countries.

Ukrainian Foreign Ministry spokeswoman Maryana Betsa said on November 21 that a Belarusian diplomat had been declared persona non grata and expelled from Ukraine in response to the Belarusian government's decision the previous day to expel diplomat Ihor Skvortsov from the Ukrainian Embassy in Minsk.

Belarusian officials said on November 20 that Skvortsov had been allegedly involved in espionage.

According to Minsk, Skvortsov coordinated the "spying activities" of Ukrainian journalist Pavlo Sharoyko, who Belarusian authorities accused of being a military intelligence agent -- a claim rejected by Kyiv.

Sharoyko's detainment was first reported on November 17 by Zurab Alasania, the director of the Public Broadcasting Company of Ukraine.

Belarus-based rights group Charter97 quoted Sharoyko's colleagues as saying he had been working on stories related to the search for Pavlo Hryb, a 19-year-old Ukrainian citizen who disappeared in Belarus after being arrested and was later found to have been sent to Russia, where he was charged with terrorism-related offenses.

Relations between Russia, Belarus, and Ukraine -- mostly Slavic former Soviet republics with deep historical and cultural ties -- have been strained since Moscow seized control of Ukraine's Crimea region and threw its support behind armed separatists in eastern Ukraine in 2014.